High electrochemical activity of the oxide phase in model ceria–Pt and ceria–Ni composite anodes
nature materials
(2011)
doi:10.1038/nmat3184
William C. Chueh, Yong Hao, WooChul Jung & Sossina M. Haile
1643.full.pdf[/filename]见解:
目前使用的固体氧化物燃料电池电极材料大多是金属+铈基离子电子导体材料,来自加州理工学院的 Professor Haile 及其合作者通过改善氧化铈基电极材料的结构参数和界面,只是使用纯的氧化铈基电极也能很好的达到催化效果和电化学性能。使用纯的氧化铈电极的另一好处是氧化还原和和循环的稳定性显著提高。
纳米科学也开始在高温固体燃料电池体现作用
摘要:
Fuel cells, and in particular solid-oxide fuel cells (SOFCs), enable high-efficiency conversion of chemical fuels into useful
electrical energy and, as such, are expected to play a major role in a sustainable-energy future. A key step in the fuel-cell
energy-conversion process is the electro-oxidation of the fuel at the anode. There has been increasing evidence in recent
years that the presence of CeO2-based oxides (ceria) in the anodes of SOFCs with oxygen-ion-conducting electrolytes
significantly lowers the activation overpotential for hydrogen oxidation. Most of these studies, however, employ porous,
composite electrode structures with ill-defined geometry and uncontrolled interfacial properties. Accordingly, the means by
which electrocatalysis is enhanced has remained unclear. Here we demonstrate unambiguously, through the use of ceria–metal
structures with well-defined geometries and interfaces, that the near-equilibrium H2 oxidation reaction pathway is dominated
by electrocatalysis at the oxide/gas interface with minimal contributions from the oxide/metal/gas triple-phase boundaries,
even for structures with reaction-site densities approaching those of commercial SOFCs. This insight points towards ceria
nanostructuring as a route to enhanced activity, rather than the traditional paradigm of metal-catalyst nanostructuring.
[ Last edited by xiajimu on 2011-12-28 at 16:40 ] |